1. Field of the Invention
The invention relates generally to the field of hydrocarbon production. More specifically, the present invention relates to a downhole actuating device comprising an electroactive polymer.
2. Description of Related Art
With reference to FIG. 1, one example of a prior art actuating device is shown therein. There a downhole tool 10 is shown disposed in a well bore 5 tethered or supported with a wire line 12. As is well known in the art, such downhole tools can be in the form of an elongated apparatus known in the art as a sonde, where the actuating device is disposed within the sonde. With regard to the specific example of FIG. 1, the actuating device illustrated therein is a clamping device 14. The clamping device 14 comprises a linkage arm 18 pivotally connected to a clamping arm 16. The clamping device 14 operates by angular movement of the linkage arm 18. The linkage arm 18 is powered by a motor 24 via a drive nut 22 and drive screw 20. As shown, the motor provides a rotating force onto the drive screw 20, which by virtue of its threaded connection with the drive nut 22, upwardly motivates the drive nut 22 which in turn moves the linkage arm 18. With regard to this particular application, the sonde is an acoustic device having geophones. As is known in the art, proper operation of the geophones and/or accelerometers necessitates that the sonde be tightly pressed (i.e. coupled) against one side of the well bore 5.
However, one of the problems with such prior art devices is the large amount of weight and volume required by the clamping device 14 and its associated hardware. With regard to the clamping device 14 as shown, the motor 24 often occupies a substantial space and can have a large weight. Therefore there exists a need for the use of downhole actuation devices that can be utilized without the requirements of large weight and/or volume as well as the associated power requirements.